W. River Parkway could be closed all year

With a detour on W. River Parkway diverting more than 6,000 motorists a day, Minneapolis park officials say they may not have a fix in place yet this year for an unstable slope that closed the road in June.

Park officials said Friday that they're analyzing soil borings and other data to try to determine how they will stabilize the hillside so traffic can resume.

"We all wish we had a firm answer on what the next steps will be," said Justin Long, an assistant park superintendent.

He said the Park Board expects to begin construction yet this fall on a repair that will keep the hillside stable, but that work likely will not be completed until spring. Asked if the parkway would repen by the end of the year, Long said he wasn't sure.

"We understand that this is a huge commuter route and it is a huge inconvenience to our constitutents," Long said. Besides thousands of motorists, hundreds of cyclists and pedestrians also are detoured.

Long said that the section of parkway, which lies below Fairview Health Services downriver from 4th Street S., may adjoin a quarry that was mined for limestone when walls were built for the parkway in the 1930s. The area was then backfilled with soil.

Initially, park officials have used stakes, sandbags and concrete barriers to try to pin the soil in place with a fabric casing. But when it rains, groundwater flowing laterally through the ground washes more soil down the slope and against barriers on the verge of the road. Sometimes the flow has been strong enough to nudge the concrete barriers lining the bottom of the hill, Long said. The Park Board has trucked the silt away, Long said.

"This is very loose material and there's still signs of movement," he said.

Given that situaiton, park officials don't feel it's safe to reopen the roadway, Long said, although the pavement itself wasn't damaged. But other damage to nearly railings and to rebuild the hillside is estimated to cost aobut $4 million and the park system is documenting what it does to address the problem to claim federal disaster reimbursement.